The present invention relates generally to the field of esophageal prosthetics. More specifically, a prosthesis delivery device is disclosed for submucosal insertion of a prosthetic bulking device.
Gastroesophageal reflux is a physical condition in which stomach acids reflux, or flow back from the stomach into the esophagus. Frequent reflux episodes (two or more times per week), may result in a more severe problem known as gastroesophageal reflux disease (GERD). Gastroesophageal reflux disease is the most common form of dyspepsia, being present in approximately 40% of adults in the United States on an intermittent basis and some 10% on a daily basis.
Dyspepsia, or heartburn, is defined as a burning sensation or discomfort behind the breastbone or sternum and is the most common symptom of GERD. Other symptoms of GERD include dysphasia, odynophagia, hemorrhage, water brash, and pulmonary manifestations such as asthma, coughing or intermittent wheezing due to acid aspiration. Dyspepsia may also mimic the symptoms of a myocardial infarction or severe angina pectoris. Many factors are believed to contribute to the onset of GERD including transient lower esophageal sphincter relaxations, decreased LES resting tone, delayed stomach emptying, and an ineffective esophageal clearance. Many in the field agree, however, that the primary cause of GERD is the lack of competency of the lower esophageal sphincter.
The lower esophageal sphincter, or valve, is comprised of smooth muscle located at the gastroesophageal (GE) junction and functions to allow food and liquid to pass into the stomach but prevent regurgitation of stomach contents. At rest, the LES maintains a high-pressure zone between 10 and 30 mm Hg above intragastric pressure. Upon deglutition, the LES relaxes before the esophagus contracts, allowing food to pass through into the stomach. After food passes into the stomach, the LES contracts to prevent the stomach contents and acids from regurgitating into the esophagus. The mechanism of LES opening and closing is influenced by innervation via the vagus nerve and hormonal control of gastrin and possibly other gastrointestinal hormones.
The severity of GERD varies from patient to patient and in extreme cases complications including esophageal erosion, esophageal ulcers, and esophageal stricture are observed. Esophageal stricture is a serious condition which results from prolonged exposure of the esophageal mucosa to acid reflux. The most common clinical manifestation of stricture is dysphasia. Unlike dysphasia from non-strictured esophageal reflux, dysphasia caused by stricture is progressive in that the size of a bolus which can pass into the stomach progressively becomes smaller. In addition to esophageal erosion and ulceration, prolonged exposure of the esophageal mucosa to stomach acid can lead to a condition known as Barrett""s Esophagus. Barrett""s Esophagus is an esophageal disorder that is characterized by the replacement of normal squamous epithelium with abnormal columner epithelium. This change in tissue structure is clinically important not only as an indication of severe reflux, but the appearance of columner epithelium in the esophagus is indicative of cancer.
Current methods to treat gastroesophageal reflux disease consist of lifestyle changes such as weight loss, avoidance of certain foods that exacerbate the symptoms of GERD and avoidance of excessive bending. Elevation of the head of the bed helps prevent nocturnal reflux. While these avoidance strategies may be helpful, there is relatively little data supporting the efficacy of lifestyle modification alone for the treatment of GERD.
Medications for the treatment of GERD have been administered for years with little or no success. Conventional antacids, such as TUMS(copyright) and ROLAIDS(copyright), produce short-term relief, but often have side effects including diarrhea and constipation. H2 receptor antagonists, such as Cimetidine and Ranitidine, are relatively more effective in controlling GERD symptoms but these symptomatic therapies fail to treat the underlying cause of the disease. More powerful secretory inhibitors, such as the proton pump inhibitors Omeprazole and Lansoprazole are more effective than the H2 antagonists but these drugs are expensive and, in the long term, produce negative side effects.
Surgery has become an attractive alternative for the treatment of GERD when lifestyle modification and medications fail to treat this debilitating condition. There are numerous reflux operations available which perhaps reflect the inadequacy of any one procedure to totally control the problem. The most commonly performed operation, Nissen Fundoplication, has been effective, but is often complicated by stricture formation or gas bloat syndrome. A laparoscopic Nissen procedure has also been developed, adding another dimension of difficulty, and long-term results remain questionable. In addition, a percutaneous laparoscopic technique has been developed. (See, for example, U.S. Pat. No. 5,006,106 to Angelchik). Minimally invasive techniques, such as transesophageal implantation of a prosthetic valve have also been attempted. (See, for example, U.S. Pat. No. 4,846,836 to Reich). Despite extensive attempts in the field to treat and prevent GERD, existing forms of treatment all have shortcomings.
In view of the foregoing, and notwithstanding the various efforts exemplified in the prior art, there remains a need for a minimally invasive bulking prosthesis and deployment methodology for transesophageal delivery into the vicinity of the lower esophageal sphincter.
In accordance with one aspect of the present invention, there is provided a method of treating gastroesophageal reflux disease. The method comprises the steps of providing a catheter having an opening thereon, and positioning the opening at a treatment site in the esophagus. Tissue is drawn at the treatment site into the opening, and an expandable hydrogel bulking device is deployed into the tissue at the treatment site, in the vicinity of the lower esophageal sphincter.
The deploying step may comprise inserting two or more bulking devices. The bulking device may comprise an expandable hydrogel rod, which may have an expansion ratio of at least about 100%. In certain embodiments, the hydrogel rod has an expanded length within the range of from 0.5 cm to about 5 cm, and an expanded width within the range of from about 0.2 cm to about 2 cm. In one embodiment, the hydrogel rod has an unexpanded diameter of about 2 mm.
In accordance with another aspect of the present invention, there is provided a method of treating gastroesophageal reflux disease. The method comprises the steps of providing an implantation device having a tissue stabilization surface thereon, positioning the device in the esophagus and drawing tissue toward the tissue stabilization surface. An expandable hydrogel esophageal bulking device is inserted into the tissue in the vicinity of the lower esophageal sphincter.
In one application, the drawing tissue step is accomplished using suction. The esophageal bulking device may comprise an expandable hydrogel rod.
In accordance with a further aspect of the present invention, there is provided a method of reestablishing lower esophageal sphincter function. The method comprises the steps of transesophageally introducing a deployment device to a treatment site in the vicinity of the lower esophageal sphincter. Tissue is drawn into a cavity on the deployment device, and an access pathway is provided through the tissue. An expandable bulking device is introduced into the wall of the esophagus in the vicinity of the cavity, so that the bulking device cooperates with the lower esophageal sphincter to reestablish sphincter function.
In one implementation of the method, the bulking device increases the closing pressure of the sphincter along an axial length of at least about 1.5 cm. The closing pressure following implantation of the bulking device may be at least about 10 mm Hg. In certain applications, the closing pressure in the lower esophageal sphincter following implantation is within the range of from about 10 mm Hg to about 30 mm Hg. In one application, the closing pressure following implantation of the bulking device is at least about 18 mm Hg along a length of at least about 2 cm.
In accordance with another aspect of the present invention, there is provided a method of treating gastroesophageal reflux disease. The method comprises the steps of identifying a patient having gastroesophageal reflux disease, and stabilizing mucosa at a treatment site in the vicinity of the patient""s lower esophageal sphincter by drawing mucosa into contact with a tissue stabilizing surface. A tubular body is introduced through the mucosa, and at least one expandable bulking device is deployed from the tubular body beneath the stabilized mucosa.
The deploying step may comprise implanting at least one expandable rod. The rod may comprise hydrogel. The bulking device may have an expansion ratio of at least about 100%. In certain embodiments, the hydrogel rod has an expanded length within the range of from about 0.5 cm to about 5 cm. The rod may have an expanded width within the range of from about 0.2 cm to about 2 cm. In certain embodiments, the bulking device has a length to thickness ratio of no more than about 15:1.
Further features and advantages of the present invention will become apparent to those of skill in the art in view of the detailed description of preferred embodiments which follows, when considered together with the attached drawings and claims.